This invention concerns olefin polymer production methods and olefin polymers, and to be more detailed, concerns a process of producing olefin polymers by which olefin polymers can be obtained at high polymerization activity, a method of producing olefin polymers with a silyl group at the terminal, and silyl-terminated olefin polymers.
Known prior methods of producing ethylene homopolymers, ethylene.xcex1-olefin copolymers, propylene homopolymers, propylene.xcex1-olefin copolymers, and other olefin polymers include methods of polymerizing olefins under the presence of a titanium catalyst comprising an organoaluminum compound and a solid titanium catalyst component containing magnesium, a halogen, and an electron donor, or under the presence of a vanadium catalyst comprising a vanadium compound and an organoaluminum compound. Also is known a method of polymerizing an olefin under the presence of a metallocene catalyst comprising transition metal compound such as zirconocene and an orgnaoaluminum oxycompound (aluminoxane), and it is known that the use of a metallocene catalyst enables production of an oiefin polymer of high molecular weight at high activity and that the olefin polymer obtained has a narrow molecular weight distribution and a narrow composition distribution.
Though hydrogen is generally used to adjust the molecular weight in the production of an olefin polymer, if for example a polymer of low molecular weight is to be produced using the catalyst which is capable for giving high molecular weight such as the abovementioned metallocene catalyst, a large amount of hydrogen will have to be used. In this case, since the concentration of hydrogen in the polymerization system-will be high, significant lowering of the polymerization activity or undesirable rapid hydrogenation of a functional group may occur and thus favorable results may not be obtained. A chain transfer agent is thus desired with which the polymerization activity will not be lowered much in the production of an olefin polymer of low molecular weight using the catalyst which is capable for giving high molecular weight such as the metallocene catalyst.
With regard to chain transfer agents, the use of a dialkylzinc compound in the production of an ethylene copolymer under the presence of a titanium catalyst is. described in Japanese Laid-open Patent Publication No. 227604/1992, and the use of a silane compound in the production of an ethylene (co)polymer under the presence of a metallocene catalyst is described in Japanese Laid-open Patent Publication No. 95514/1997. Of the above, with the method of using a silane compound, the metallocene compound to be used is limited to being a metallocene compound having a (substituted) cyclopentadienyl group, and any effects attained by coexistence of hydrogen are not described in the corresponding publication.
Upon carrying out examinations in view of such prior arts, the present inventors have found that by using an organosilicon compound or a dialkylzinc compound in combination with hydrogen in the (co)polymerization of an olefin under the presence of a transition metal compound, an olefin polymer of low molecular weight or an olefin polymer with a silyl group at the terminal can be produced at high polymerization activity. The present inventors have also found that by using an organosilicon compound or a dialkylzinc compound in the (co)polymerization of an olefin under the presence of a specific transition metal compound containing a ligand having a cyclopentadienyl skeleton, an olefin polymer of low molecular weight or an olefin polymer with a silyl group at the terminal can be produced at high polymerization activity, and have thus come to complete the present invention.
An object of this invention is to provide a process for producing an olefin polymer by which olefin polymers can be obtained at high polymerization activity, a process for producing an olefin polymer by which olefin polymers having a silyl group at the terminal can be obtained at high polymerization activity, and silyl-terminated olefin polymers.
A process for producing an olefin polymer according to the present invention is characterized in-that olefin polymerization or copolymerization is carried out under the presence of:
a catalyst comprising
(A) a compound of a transition metal selected from among groups 3 to 10 of the periodic table (with lanthanides and actinides being included in group 3) and
(B) at least one compound selected from among
(B-1) organoaluminum oxycompounds,
(B-2) compounds that react with the abovementioned compound (A) to form an ion pair, and
(B-3) organoaluminum compounds and under the coexistence of
(C) an organosilicon compound respresented by the general formula (I) given below, or (D) a dialkylzinc compound represented by the general formula (II) given below,
R1R2R3SiHxe2x80x83xe2x80x83(I)
xe2x80x83(In the above formula, R1, R2, and R3 may be the same or may differ from each other, with each indicating a hydrogen atom, an alkyl group of 1 to 4 carbon atoms, an aryl group of 6 to 12 carbon atoms, an alkylaryl group of 7 to 20 carbon atoms, an arylalkyl group of 7 to 20 carbon atoms, an alkoxy group of 1 to 4 carbon atoms, a phenoxy group, a fluoroalkyl group of 3 to 6 carbon atoms, a dialkylamino group containing alkyl groups of 1 to 4 carbon atoms, or a diorganopolysiloxane chain containing 1 to 10 siloxane units.)
ZnR4R5xe2x80x83xe2x80x83(II)
xe2x80x83(In the above formula, R4 and R5 may be the same or may differ from each other, with each indicating an alkyl group of 1 to 20 carbon atoms.) and
(E) hydrogen.
In the present invention, preferably the abovementioned compound (A) is a transition metal compound (A-1) of a transition metal selected from among groups 3 to 10 of the periodic table (with lanthanides and actinides being included in group 3) containing a ligand having a cyclopentadienyl skeleton,
more preferably the abovementioned compound (A) is a compound (A-2) of a transition metal selected from among group 4 of the periodic table containing a ligand having a cyclopentadienyl skeleton, and even more preferably, the abovementioned compound
(A) is a compound (A-3) represented by the following general formula (IV) or (V). 
(In the formula (IV), M1 indicates an atom of a transition metal selected from among group 4 of the periodic table, R11 to R20 may be the same or may differ from each other, with each indicating a hydrocarbon group of 1 to 40 carbon atoms, a halogenated hydrocarbon group of 1 to 40 carbon atoms, an oxygen-containing group, a sulfur-containing group, a silicon-containing group, a halogen atom, or a hydrogen atom, the adjacent two groups among R11 to R20 may be bonded mutually to form an aromatic group along with the carbon atoms bonded to each group, each of such an aromatic group may be substituted with a hydrocarbon group of 1 to 40 carbon atoms, a halogenated hydrocarbon group of 1 to 40 carbon atoms, an oxygen-containing group, a sulfur-containing group, a silicon-containing group, or a halogen atom, X1 and X2 may be the same or may differ from each other, with each indicating a hydrocarbon group of 1 to 20 carbon atoms, a halogenated hydrocarbon group of 1 to 20 carbon atoms, an oxygen-containing group, a sulfur-containing group, a silicon-containing group, a hydrogen atom, or a halogen atom, and Y1 indicates a bivalent hydrocarbon group of 1 to 20 carbon atoms, a bivalent halogenated hydrocarbon group of 1 to 20 carbon atoms, a bivalent silicon-containing group, a bivalent germanium-containing group, a bivalent tin-containing group, xe2x80x94Oxe2x80x94, xe2x80x94COxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94SOxe2x80x94, SO2xe2x80x94, xe2x80x94Gexe2x80x94, xe2x80x94Snxe2x80x94, xe2x80x94NR21xe2x80x94, xe2x80x94P(R21)xe2x80x94, xe2x80x94P(O)(R21)xe2x80x94, xe2x80x94BR21xe2x80x94, or xe2x80x94AlR21xe2x80x94 (where the R21""s may be the same or may differ from each other, with each indicating a hydrocarbon group of 1 to 20 carbon atoms, a halogenated hydrocarbon group of 1 to 20 carbon atoms, a hydrogen atom, or a halogen atom).
In the formula (V), M1 indicates a transition metal atom selected from among group 4 of the periodic table, Cp indicates a cyclopentadienyl group or derivative thereof, which is xcfx80-bonded to M1, Z1 indicates an oxygen atom, a sulfur atom, a boron atom or a ligand containing an atom of group 14 of the periodic table, Y2 is a ligand containing an atom selected from among the nitrogen atom, phosphorus atom, oxygen atom and sulfur atom, and the X3""s, may be the same or may differ from each other, with each indicating a hydrogen atom, a halogen atom, a hydrocarbon group of 1 to 20 carbon atoms and may have one or two or more or double bonds, a silyl group containing 20 or less silicon atoms, or a germyl group containing a germanium atom.).
Another process for producing an olefin polymerization according to the present invention is characterized in that an olefin of 3 or more carbon atoms is polymerized or two or more olefins are copolymerized under the presence of a catalyst comprising an abovementioned transition metal compound (A), at least one compound (B) selected from among organoaluminum oxycompounds (B-1), compounds (B-2) that react with the abovementioned compound (A) to form an ion pair, and organoaluminum compounds (B-3), and under the coexistence of an abovementioned organosilicon compound (C) and hydrogen (E) to produce a silyl-terminated olefin polymer, wherein the terminal of which is a residual group of the organosilicon compound (C) represented by the general formula (I) given above and which has an isotactic index of 95 of more.
Still another process for producing an olefin polymer according to the present invention is characterized in that olefin polymerization or copolymerization is carried out under presence of a catalyst comprising
(A-i) a transition metal compound of a transition metal selected from among groups 3 to 10 of the periodic table (with lanthanides and actinides being included in group 3) containing a ligand having a cyclopentadienyl skeleton (with the exception of such a compound having two indenyl groups that are bonded via ethylene), and
(B) at least one compound selected from among
(B-1) organoaluminum oxycompounds,
(B-2) compounds that react with the abovementioned compound (A-i) to form an ion pair, and
(B-3) organoaluminum compounds and under the coexistence of
(C) an organosilicon compound represented by the general formula (I) given below, or (D) a dialkylzinc compound represented by the general formula (II) given below,
xe2x80x83R1R2R3SiHxe2x80x83xe2x80x83(I)
xe2x80x83(In the above formula, R1, R2, and R3 may be the same or may differ from each other, with each indicating a hydrogen atom, an alkyl group of 1 to 4 carbon atoms, an aryl group of 6 to 12 carbon atoms, an alkylaryl group of 7 to 20 carbon atoms, an arylalkyl group of 7 to 20 carbon atoms, an alkoxy group of 1 to 4 carbon atoms, a phenoxy group, a fluoroalkyl group of 3 to 6 carbon atoms, a dialkylamino group containing alkyl groups of 1 to 4 carbon atoms, or a diorganopolysiloxane chain containing 1 to 10 siloxane units.)
ZnR4R5xe2x80x83xe2x80x83(II)
xe2x80x83(In the above formula, R4 and R5 may be the same or may differ from each other, with each indicating an alkyl group of 1 to 20 carbon atoms.) and
under the non-presence of hydrogen.
In the present invention, preferably the abovementioned compound (A-i) is a transition metal compound (A-ii) of a transition metal selected from among group 4 of the periodic table containing a ligand having a cyclopentadienyl skeleton (with the exception of such a compound having two indenyl groups that are bonded via ethylene), and
more preferably, the abovementioned compound (A-i) is a compound (A-iii) represented by the following general formula (IV) (with the exception of such a compound having two indenyl groups that are bonded via ethylene) 
(In the above formula, M1 indicates an atom of a transition metal selected from among group 4 of the periodic table, R11 to R20 may be the same or may differ from each other, with each indicating a hydrocarbon group of 1 to 40 carbon atoms, a halogenated hydrocarbon group of 1 to 40 carbon atoms, an oxygen-containing group, a sulfur-containing group, a silicon-containing group, a halogen atom, or a hydrogen atom, the adjacent two groups among R11 to R20 may be bonded mutually to form an aromatic group along with the carbon atoms bonded to each group, each of such an aromatic group may be substituted with a hydrocarbon group of 1 to 40 carbon atoms, a halogenated hydrocarbon group of 1 to 40 carbon atoms, an oxygen-containing group, a sulfur-containing group, a silicon-containing group, or a halogen atom, X1 and X2 may be the same or may differ from each other, with each indicating a hydrocarbon group of 1 to 20 carbon atoms, a halogenated hydrocarbon group of 1 to 20 carbon atoms, an oxygen-containing group, a sulfur-containing group, a silicon-containing group, a hydrogen atom, or a halogen atom, and Y1 indicates a bivalent hydrocarbon group of 1 to 20 carbon atoms, a bivalent halogenated hydrocarbon group of 1 to 20 carbon atoms, a bivalent silicon-containing group, a bivalent germanium-containing group, a bivalent tin-containing group, xe2x80x94Oxe2x80x94, xe2x80x94COxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94SOxe2x80x94, S2xe2x80x94, xe2x80x94Gexe2x80x94, xe2x80x94Snxe2x80x94, xe2x80x94NR21xe2x80x94, xe2x80x94P(R21)xe2x80x94, xe2x80x94P(O)(R21)xe2x80x94, xe2x80x94BR21xe2x80x94, or xe2x80x94AlR21xe2x80x94 (where the R21""s may be the same or may differ from each other, with each indicating a hydrocarbon group of 1 to 20 carbon atoms, a halogenated hydrocarbon group of 1 to 20 carbon atoms, a hydrogen atom, or a halogen atom).)
Yet another process for producing an olefin polymer according to the present invention is characterized in that an olefin of 3 or more carbon atoms is polymerized or two or more olefins are copolymerized under the presence of a catalyst comprising an abovementioned transition metal compound (A-i), at least one compound (B), selected from among organoaluminum oxycompounds (B1), compounds (B-2) that react with the abovementioned compound (A-i) to form an ion pair, and organoaluminum compounds (B-3), under the coexistence of an abovementioned organosilicon compound (C), and under the non-presence of hydrogen (E) to produce a silyl-terminated olefin polymer, wherein the terminal of which is a residual group of the organosilicon compound (C) expressed by the general formula (I) given above and which has an isotactic index of 95 of more.
A silyl-terminated olefin polymer according to the invention is characterized in that the terminal is a residual group of an organosilicon compound (C) represented by the general formula (I) given above and in having an isotactic index of 95 or more.
Such a silyl-terminated olefin may for example be produced by the process for producing the olefin polymer such as those described above.